The conventional hand-pump spray-bottle and pressured-gas spray-can employ a single dip tube with an open end that extends into the liquid to be expelled. When the container is held upright, the open end of the dip tube extends into the liquid and, when the pump or valve is actuated, expels the liquid. However, if the container is inverted or held at any orientation where the open end of the dip tub is not immersed in the liquid, air or the pressurizing gas will be expelled instead of the desired liquid There is great interest in the industry for a spray bottle that can operate in any orientation. Several patents have been granted (e.g. Grothoff U.S. Pat. No. 4,775,879 and Ramsey U.S. Pat. No. 3,733,013) for containers that can operate either upright or completely inverted. These inventions require expensive unreliable check valves and still are limited to operation when they are completely vertical or completely inverted. To date there is no known spray bottle available which will operate at all orientations except for the one described in a recent patent application by Ellion and Pfautz (Ser. No. 08/241,845 dated May 12, 1994). This application describes a feed system that employs filters at the liquid inlets having pores of a size that prevent gas from entering the wetted filters as the result of surface tension forces, but does allow the liquid to pass freely. While such a container is workable and valuable, the cost of the filters may make its application to the mass market economically infeasible.
Additionally, the size of the filter pores must be changed for each liquid which has a different surface tension. Another disadvantage is that some media to be dispensed contain solid particles that would plug the pores and make the system inoperable. Consequently, one feed system will not be universally usable for all media.
The use of a flexible bladder to allow liquids to be expelled by action of a pump or a pressurized gas is well known for zero-gravity satellites and for vehicles such as airplanes which are not always oriented in the same position. A summary article is given in the Journal of Spacecraft and Rockets vol. 8 No. 1 Feb. 2, 1971 pages 83-88 by S. Debrok.
The use of flexible bladders also is well known for many other applications such as water pump systems on ranches where the bladder separates the air in the pressure tank from the water in order to prevent the water from becoming saturated with high pressure air which would come out of solution when expelled from the faucet with the undesirable effect of effervescence.
A flexible bladder has also been used in baby milk bottles to prevent the baby from ingesting air. There is, however, no known application of a flexible bladder for hand-held pump spray bottles or for pressurized aerosol cans in order to allow them to operate at any orientation.
It is the principal object of this invention to provide a universal hand-held dispensing container that is useful to provide a stream or a spray of any liquid medium without gas, when the bottle is held at any orientation.
It is an optional object of this invention to provide a feed system that operates automatically without requiring manipulation on the part of the user.
It is still another optional object of this invention to provide for the spray bottle that can be refilled with additional liquid.
It is yet another optional object of this invention to be able to operate the spray bottle on earth, and consequently in a gravity field or at any gravity level above or below the earth's gravity level.
It is another optional object of this invention to provide a bladder which can be made of inexpensive organic plastic material, and in such thin sections as to make the bladder very affordable.